| The present study has developed a method based on the Headspace Solid Phase Microextraction coupled with Gas chromatography/Mass spectrum (HS-SPME-GC/MS) for the analysis of 4 odourous compounds in water, MIB,β-Cyclocitral, GEO andβ-Ionone. The SPME experimental procedures were performed with a 50/30μm DVB /CAR/PDMS fiber for 40 min at 65℃using 25 mL sample added 7.0g NaCl, stirring at 500 rpm. Quantitative analysis of the 4 compounds was obtained by Full Scan Mode and Selective Ion Storage (SIS), respectively. According to the analysis results, the method determination limits (MDLs) of the SIS for MIB,β-Cyclocitral, GEO andβ-Ionone were 2.5 ng/L, 1.9 ng/L, 1.0 ng/L and 2.7 ng/L,respectively, which were better remarkably than that of Full Scan Mode, the recoveries are between 93.76% and 95.66%. The linear ranges of the SIS for the 4 odourous compounds were from 4 ng to 1000 ng with the correlation coefficients all above 0.99. Based on the above results, a Sensory Gas Chromatography (Sensory-GC) analytical method was developed and applied in determinations of samples from Tai Lake. The results indicated that the odours of samples included stench, burnt taste, earthy, musty, aroma and sweet. The 4 odourous compounds were determined in all samples and the highest concentrations were 180.43 ng/L, 389.14ng/L, 71.45ng/L and 58.11ng/L for MIB,β-Cyclocitral, GEO andβ-Ionone, respectively.The volatile decomposed compounds containning Nitrogen and Sulfur element were identified and the variation trends of their concentrations were studied in this study. Results of the study demonstrated that the major volatile odourous decompositions were dimethyl amine, dimethyl disulfide, dimethyl trisulfide and dimethyl tetrasulfide. In the decomposition process, there were the same variation trends of concentrations for the 4 compounds and their highest concentrations appeared early with the increase of decomposition temperature.
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